A parasite I did not face before?

[Drakoi]

Hey there,

I just did a scrape to a friend's koi.

The one seems infested with costia as nothing I have seen. You could see the fish was so weak because of it. it was really sad.

The other fish that had a problem did not have costia though. It had something else.

Under x400 I could see a circle, with some kind of bubbles at the place of his head and "maybe" tiny legs around him.

I try to draw a picture of what I see but I dont know if it is any helpful.

[Drakoi]

something like this maybe ? Even though I could not see that circle thing inside his "stomach"